Automatic tension control



Feb. 29, 1944. E 2,343,181

AUTOMATIC TENSION CONTROL Filed April 5, 1940 2 Sheets-Sheet l mam bow W B. Hylnz,

Feb. 29, 1944. B HE|NZ 2,343,181

AUTOMATIC TENS ION CONTRO L Filed April 3, 1940 2 Sheets-Sheet 2 Patented Feb. 29, 1944 uumzo STATES PATIENT OFFICE noromnc TENSION common.

Winfield n. Heinz, Bound Brook, N. .l. Application April 3, 1940, Serial No. 327,708

19 Claims.

This invention relates to the automatic control of tension in traveling strand or strip materials such as textile fabrics, paper, sheet metal, or wire. Maintenance of constant tension in traveling materials is important in connection with machines which operate in some phases on' the material. It is usual in these machines to unreel and reel up the material before and after the operation and during the process the tension must be maintained constant regardless of the diameter of the unwinding and winding reels and thevarying friction which maybe applied to the material by the operation of the machine.

An object of this invention is to provide a control device maintaining constant tension in traveling material regardless of various strains to which the material is subjected.

Another object of the invention is to provide a vtension detector engaged by the traveling material and movable in response to changes in tension therein to operate means for controlling the tension in the material.

A further object of the invention is to couple the tension detector to the tensioning means to prevent overcorrection of tension variations and to render the detector more responsive to tension changes produced by the tensioning means.

A secondary object of the invention is to make possible the use of higher speeds in handling traveling materials.

In carrying this invention into effect tensioning means are provided for controlling the tension in the traveling material. This tension control device may consist of a brake eng-ageable with an unwinding reel or variable clutch means to control the torque to a winding reel. A power operated actuator is provided for the tensioning means, and may be resiliently coupled thereto. Means is provided to control the motor by varying the power supplied to it.

A tension measuring device is provided in the form of a member engaged in a loop of the traveling material. This member is movable by the tension in the material and is resiliently constrained so that its movement is proportional to the force exerted on it by the tension. The detector is operatively connected to the means for varying the power to the tensioning motor and the detector thereby maintains a constant tension.

in the material through its control of the tensioning means. The tensioning motor is coupled to the detector so that a movement of the motor to alter the tension in the material accelerates movement of the detector so that it will be..ad-.

justed more quickly than if the detector were movable only in response to corrective change in tension of the traveling material. Consequently, overcorrection of tension variations is prevented and at the same time transient effects from the inertia of the tension detector on the traveling material are avoided.

Several embodiments of my invention are illustrated in the accompanying drawings in which:

Fig. 1 is a diagrammatic representation of my invention applied to an unwinding reel;

' Fig. 2 is a diagrammatic representation of a. further embodiment of my invention applied to a winding reel;

Fig. 3 is a diagrammatic view of another embodiment of my invention applied to an unwinding reel; and

Fig. 4 is another embodiment of my invention applied to an unwinding reel.

In Fig. 1 strand or strip material I is shown traveling from unwinding reel 2 to winding reel 3. Power may be applied to shaft 4 of the winding reel. A brake 5 is provided for acting on the brake drum 6 mounted on unwinding reel 2 to control the tension in the traveling material.

Brake 5 is operated by the piston l of the fluid pressure operated motor 8. As shown, the piston may be resiliently connected to the brake by spring 9.

The traveling material is passed over the fixed supporting rollers Ill and II to provide a loop engaging movable roller [2. The movable roller constitutes the tension detector. The tension in the traveling material exerts a force upwardly on roller I2, which is resiliently opposed by spring l3 acting through member H in which roller I 2 is joumaled. The resilient action of spring l3 permits roller i2 to change its position proportionately to changes in tension in the material. The movable roller therefore constitutes an accurate device for measuringthe tension present in the material.

Fluid pressure for operating the motor 8 is supplied by conduit l5. Connecting the conduit 15 are pressure supply lines l6 and i! for conducting fluid pressure to each side of piston l. The action of the piston is controlled by the pressure difiereniiial between supply lines l8 Iii)- andl'l. The pressures in lines is and I 1 are 1- controlled by vane 20 in cooperation with the opposed vents l8 and I! in lines l6 and I1, re-

- :spectively.

In its-intermediate position, vane 20 permits equal flow from lines I8 and I1, and equalizes the pressure in these lines. As vane 20 is moved closer to one of the vents the flow therefrom is decreased to raise the pressure in the corresponding supply line and the flow from the other vent is increased to lower the pressure in the other supply line. In this way, vane 20 proportions the pressures in lines l6 and I1 and thereby controls the actuation of piston I.

The supply of pressure to lines It and II is preferably restricted, and for this purpose orifices 2| and 22 are provided. As shown, vents l3 and I3 are larger than the orifices so that complete control of the pressures in lines l6 and H is ob-' tained over a wide range by movement of vane Vane 20 is carried by member 23 which is Journaled on a fixed pivot 24. Member 23 is attached to member l4 by the pivot 26. In this way, tension detector roller |2 controls the operation of motor 3 and, through the action of brake 6, the tension in the traveling material.

For coupling motor 3 to the tension detector |2, there is provided lever 26 attached to connecting rod 30 by pin 23 and engaging spring l3 at 28. Lever 26 is intermediately joumaled on pivot 21. Through lever 26, movement of piston I to increase the tension on the material by taking up brake 6 raises roller |2 to accelerate the response in the roller to the increase in tension resulting from the application 'of brake 6.

At the same time the movement upwardly of the roller decreases the length of the loop of material engaging the same and thereby afiects the tension reversely of the action of brake 6. Corresponding efl'ects are produced on the roller l2 by a movement of piston I to reduce the tension in the material.

The operation of the device shown in Fig. 1 in response to an undesired variation of tension in the material may be described as follows: Assuming that the tension is momentarily diminished, spring |3 causes roller I! to move downwardly until the tension of the spring is decreased to a point where it is counterbalanced byv the force exerted on roller l2 by the reduced tension. This movement of roller |2 immediately alters the position of vane 20 through the action of lever 23, decreasing the flow through vent l3 and increasing the flow through vent It}. In accordance with the alteration of the position of vane 20, pressure is increased in line I! and decreased in line l6 so that a greater force is exerted on piston 1 to increase the action of brake 5 on brake drum 6. As piston I is moving to increase the action of brake 5 at the same time, through lever 26, tension on spring I3 is reduced to accelerate the upward movement of roller |2 with the increase in tension and to prevent overcorrection oi the tension by shortening the loop engaging the tension detector. As roller I2 moves up under the action of the'increased tension in the material and the movement of lever 26, member 23 restores vane 20 toward its original position, roller |2 coming to rest when the desired tension is reached.

In Fig. 2 is shown an embodiment of my tension control device applied to a winding reel. In this construction winding reel 3 is carried on shaft 4 and adapted to be driven by pulley 30. A loose belt 3| connects pulley to a driving pulley 32. The tension in belt 3| is adjusted by movable idler 33. By adjustment of the position of idler 33 the engagement of belt 3| with pulley 30 can be varied to control the torque applied to the winding reel 3.

As in the construction shown in Fig. l, I provide in Fig. 2 a movable roller |2 engaged by a loop of the .traveling material I which is supported on fixed rollers I0 and II. The movable roller is journaled in member l4 and is resilient- 1y held against movement by the tension in the material by spring l3. This construction permits the position of the roller to vary in dependency on variations of the tension in the traveling material. 1

Member l4, through member 23, journaled on the fixed pivot 24, controls the position of movable vane 20. The movable vane in coaction with the vents l8 and I9 proportions the pressures in the pressure supply lines l6 and I1, thereby controlling the actuation of piston 1 of the fluid pressure operated motor 8. Member 34, which carries the movable idler 33, is connected to piston rod 30 so that-the movable roller l2 maintains a constant tension in the traveling material by controlling the tension of belt 3| and the torque thereby applied to winding reel 3.

In order to prevent overcorrection of tension variations and to accelerate the response of the movable tension detector roller |2 to changes in tension resulting from variations in the position of movable idler 33, member 34 is coupled to spring I3 through arm 35, link 36, and lever 31. The operation of this construction'is similar to the embodiment shown in Fig. 1 with the exception that thetension is controlled by varying the torque received by winding drum 3 instead of varying the braking action on the unwinding reel. If desired, the construction shown in Figures 1 and 2 may be used in conjunction where the traveling material'is subjected to intermediate operations between its unreeling and reeling.

In Fig. 3 is shown another embodiment of my invention applied to traveling material drawn off from unwinding reel 2 by winding reel 3. The

tension in the traveling material is controlled by the action of brake 5 on brake drum 6 which is carried by the unwinding reel 2. The tension in the material is measured by movable roller |2 engaged in a loop of the traveling material supported by fixed rollers Ill and I. Movable roller I2 is joumaled in member l4. By the action of spring. engaging link 40 journaled on the fixed pivot 43 and connected to member H by pivot 4|, the movable roller I2 is resiliently held against movement by the tension in the traveling material. This construction permits the tension detector roller to vary its position in accordance with variation of the tension in the material, and, through member 23 journaled on fixed pivot 24 and connected to member l4 at 25, the position of the vane 20 is controlled. Vane 20 in cooperation with vent l3 controls the pressure in pressure supp y line H.

I provide the pressure operated motor 44 resiliently connected by spring 9 tobrake 5 for controlling the tension in the traveling material. Pressure supplied to chamber 41 by pressure supply line acts on diaphragm 45 which is connected by connecting rod 46 to spring 9. In this way the tension detector roller controls the tension on the material by varying the braking action on the unwinding reel.

In'order to stabilize the tension in the material and to prevent overcorrection of pressure variations. I provide pressure operated motor 48 for accelerating movement of the tension detector roller |2 in dependency on the action of brake 6. ,;As shown. motor 43 is provided with a diaphragm 43 which is actuatable by pressure supplied to chamber 56 from pressure supply line l1. Diaphragm 45 is connected to link 45 by connecting rod 5i attached to the link at 52. If it.

is desired to vary the eil'ective coupling to the movable tension detector roller pivots 53 and 54 on link 46 may b provided for adjusting the point at which the force exerted by motor 46 is applied to link 46.

It will be understood that through the com,- mon pressure supply line II the action of motors 44 and 46 are both controlled by movable vane 25 in cooperation with vent I9. As a result, stabilization of tension in the material and the prevention 01' overcorrection of tension variations and hunting is produced by the action 01' motor 46 in moving the tension detector roller to accelerate its response to changes in tension resulting from variation in the action of brak 5 and to ailect the tension reversely of the action of brake 5 by altering the length of the loop or traveling material engaging roller l2.

In Fig. 4 is shown a tension control device maintaining a constant tension on traveling material I through the action of brake 5 on brake I 6 carried by reel 2 as it is unwound from "reel 2 to winding reel 3. The tension in traveling material i is measured by movable roller l2 engaged by a loop of material'supported by fixed rollers ill and i I. Roller i2 is iournaled in mem ber 55 which is carried on fixed pivot 56. The tension in the traveling material is controlled by the action of pressure operated motor 44 on brake 5. Motor 44 is provided with a diaphragm 45 actuated by pressure in chamber 41 supplied by pressure supply line H. Diaphragm 45 is connected to brake 5 through connecting rod 46 and the resilient member 9. The pressure in pressure supply line I1 is controlled by movable vane 26 in cooperation with vent l9. Vane 20 is carried by movable arm 57 attached by member 58 to compressed spring 59 supported by member 65. Pressure operated motor 6! consists of an expansible bellows to which pressure is applied by conduit 62 from pressure supply line H. Through connecting rod 63 pivoted to arm 51 at 64 the pressure present in line ll exerts a force on arm 51. Coupled to arm 51 at 65 through connecting-rod 66 is bellows 61. Bellows 61 is connected by conduit 66 to bellows 69 and the system consisting of the two bellows and conduit 66 is filled with a substantially incompressible fluid.

Bellows 69 carries connecting rod coupled to member 55 by pivot H. As bellows 69 is compressed by movement of theconnecting rod ill, the pressure effects in the fluid contained in the system expand bellows 61 and through connecting rod 66 operate arm 51 to vary the position of vane in relation to vent i9 and thereby control the pressure in line ll. Through pressure operated motor 44 the pressure in line I! controls the braking action on unwinding reel 2 and thereby determines the tension in the traveling material.

For the purpose of accelerating the response of roller i2 to variations of tension in the material resulting from changes in the force applied.

to brake drum 6, bellows 6i and pressure operated motor 44 both operate in dependency on the pressure in pressure supply line ii. The coupling between bellows 6| through movable arm- 51 supported by spring 56 to bellows 61 causes bellows 69 to change its position in dependency on variation of pressure in line H. Through connecting rod 16 and member 65 the movement of bellows 56 is communicated to movable roller I! so that the latters response to variation in tension in the material produced by brake 5 is accelerated. Assuming an increase in web tension, upward movement of roller i2 causes fluid pressure to urge rod 66 downwardly. Am 51, pivoting on its left and pivot 64 is swung downwardly'against the opposition of spring 59 to move vane 26 away from vent I! with the result that pressure in line I! decreases. The motor diaphragm 45 accordingly moves upwardl and braking action is decreased to diminish the tension on the web. The lowering oi pressure in line 52 connecting with line I! permits rod 63 to move downwardly so that arm 51, swinging on its intermediate pivot 65, is urged upwardly by spring 59 to diminish the opening of vent IS. The upward thrust exerted by rod 63 and spring 56 act on rod 66 to increase the fluid pressure in line 68 and'to prevent excessive upward movement ofthe detector roll l2. As previously described, this operation of the tension detector roller avoids hunting and overcorrection of variations in tension in the material.

It will be understood that the invention is capabio of some range of modification and equivalency without departing from the essential features thereof which distinguish the same from prior tension control arrangements. The embodiments shown are therefore to be taken as merely illustrative and the scope of the invention determined from the appended claims.

It will be observed that all 01' the illustrative embodiments of the invention are so designed that the detector roller can function eiiiciently and rapidly to adjust the means controlling the tension in the material under changes of tension occurring in the material. I have found that a fluid system utilizing the several forms of pressure relief vents controlled by the detector roller is admirably suited to my purpose of maintaining the tension in the traveling material constant. The use of spring means applying a counterbalancing tension to the detector roller in opposition to the tension of the traveling material insures stability in th operation of the device, since the roller is moved in response to varia tions in the material tension from the normal only in proportion to the extent of the tension variation. Whether or not employed with such counterbalancing means the arrangement for adjusting the detector roller, and hence the control means for the tension varying means, in response to actuation of the brake or other tension varying means, serves to prevent excessive operation of the tension varying means so that variations in the tension or the traveling material are corrected rapidly and without overcorrection.

I claim:

1. A tension control device for traveling strand traveling material and movable in response tochanges of tension therein, and means independent of the material for acUusting the position of the tension responsive element operated by the tension varying means.

3. A tension control device for traveling strand and strip material comprising a tension responsive element adapted to engage the traveling material and movable in response to changes or tension therein, means actuatable in response tomovement of the tension responsive element for varying the tension in the traveling material, and means independent of the material operating in response to actuation of the tension varying means acting to cause the tension responsive element to adjust the tension varying means.

4. A tension control device for traveling strand and strip material comprising means for varying the tension in the traveling material, a tension responsive element controlling operation of the tension varying means adapted to engage the traveling material and movable in response to changes of tension therein, and means independent of the material responsive to operation of the tension varying means to effect adjustment of the tension responsive element and prevent overcorrection by the tension varying means 01' the tension in the traveling material.

5. A tension control device for traveling strand and strip material comprising means for varying the tension in the traveling material, a tension responsive element controlling operation of the tension varying means adapted to engage the traveling material and movable in response to changes of tension therein, and means independent of the material coupling the tension responsive element to the tension varying means causing movement of the tension responsive element in dependency on operation or the tension varying means to vary the tension in the material.

6. A tension control device for traveling strand and strip material comprising means for varying the tension in the traveling material, a tension responsive element controlling operation oi the tension varying means adapted to engage the traveling material .and movable in response to changes of tension therein, and means independent of the material responsive to operation of i the tension varying means to accelerate movement of the tension responsive element as the tension in the material is changed.

7. A tension control device for traveling strand and strip material comprising motor operated means for varying the tension in the traveling material, a tension responsive element adapted to engage the traveling material and movable in response to changes of tension therein, control means for said motor means responsive to movement of said element, and means independent of the material responsive to operation of the motor means as it acts to vary tension in the material for adjusting the tension responsive element.

8. A tension control device for traveling strand and strip material comprising fluid pressure operated means for varying the tension in the material, conduit means for supplying fluid pressure to said tension varying means, fluid pressure control means for controlling pressure in said conduit means, a tension responsive element for actuating the pressure control means engageable with the traveling material and movable in response to changes of tension therein, and means independent of the material coupling the tension responsive element to the tensioning means for" adiusting the position of said element in deactuating the pressure control means engageable with the traveling material and movable in response to changes of tension therein, and mechanical linkage independent of the material coupling the tension responsive element to the tensioning means for adjusting the position of said element in dependency on operation of the tensioning means in varyingthe tension in the material.

10. A tension control device for traveling strand and strip material comprising means for varying the tension in the material, a tension responsive element engageabie with the traveling material and movable in response to changes of tension therein, fluid pressure operated means for actuating the tension varying means to change the tension in the material and means operative in dependency on actuation of the fluid pressure operated means for causing movement of the tension responsive element independently of the change of tension in the material, conduit means for supplying fluid .pressure to said fluid pressure operated means, and means responsive to movement of the tension responsive element controlling the pressure in said conduit means.

11. A tension control device for traveling strand and strip material comprising means for varying the tension in the traveling material, a tension responsive element adapted to engage the traveling material and movable in response to changes of tension therein, control means for the tension varying means actuatable by the tension responsive element, and means independent of the material operated in dependency on actuation of the tension varying means to simultaneously adjust the tension responsive element and actuate said control means of the tension varying means.

12. A tension control device for traveling strand and strip material comprising means for varying the tension on the material, power-operated actuating means therefor, power control means controlling transmission of power to said actuating means, a movable tension responsive element engageable with the traveling material and movable by changes of tension in the material, said power control means being operated by the tension responsive member, and means for operatively connecting the tension responsive member to the power-operated means to resiliently oppose movement of the tension responsive member by the tension of the material and to cause movement of the tension responsive mem-' ber in response to movement of the poweroperated means.

13. A tension control device for traveling strand and strip material comprising means for varying the tension in the traveling material, fluid pressure operating means for the tension varying means, a tension responsive element adapted to engage the traveling material and movable in response to changes of tension therein, valvemeans controlling the supply of fluid pressure to said fluid pressure means operated by the tension responsive element, and means independent of the material operated by the power operated means for adjusting the position of the tension responsive element.

14. In a tension control device for traveling strand and strip material, tensioning means for controlling the tension in the material, fluid pressure operated double acting motor actuating means for the tensioning means, a first conduit means for supplying fluid pressure for actuating said motor means in one direction to increase the tension in the material, a second conduit means for supplying fluid pressure for actuating said motor means in the opposite direction to decrease'the tension in th material, opposed nozzles in the first and second conduit means for discharging fluid pressures therefrom, a movable vane member interposed between the nozzles and coacting with the nozzles to control flow therethrough and thereby proportion the pressures supplied through the first and second conduit means to the double acting motor means, and means responsive tothe tension in the material controlling the operation of the movable vane member.

15. A tension control device for traveling strand and strip material as in claim 14, further including means operated by the double acting motor actuating means independently of the material for adjusting the means controlling operation of the movable vane member.

16. A tension control device for traveling strand and strip material comprising means for varying the tension in the traveling material, fluid pressure operating means therefor, valve means controlling the supply of fluid pressure to said pressure operated means, an element for actuating said valve means adapted to engage the traveling material and being movable in response to changes of tension in the material, variable tension means applying to said element an opposing tension counterbalancing the tension in the material, and means operating independent- 1y oi the material in response to operation of the fluid pressure operated means for adjusting said valve actuating element.

17. A tension control device for traveling strand and strip material comprising power-operated means for varying the tension in the traveling material, a tension-responsive element adapted to be engaged by the traveling material and capable of movement to diflerent positions with changes in the tension in the material, and variable tension means applying to the element an opposing tension counterbalancing the tension in the material and being automatically operative to change the counter-balancing hnsion in response to changes of the tension in the material so that the position of the element is moved to an extent proportional to the extent of change 01' tension in the material, control means for the power-operated material tensioning means operated by movement of the tension-responsive element, and means operated by the tension varying means independently of the material for adjusting the position of the tension responsive element.

18. A tension control device for traveling strand and strip material comprising poweroperated means for varying the tension in the traveling material, a tension-responsive element adapted to be engaged by the traveling material and capable of movement to difierent positions with changes in the tension in the material, and variabl tension means applying to the element an opposing-tension counterbalancing the tension in the material and being automatically operative to change the counterbalancing tension in response to changes of the tension in the material so that the position of the element is moved to an extent proportional to the extent of change of tension in the material, control means for the power-operated material tensioning means operated by movement of the tension-responsive element, and means operated by the tension varying means independently of the material for adjusting the position of the tension-responsive means, said last mentioned means. being operatively connected to the tension-responsive element through said variable tension means.

19. In a tension control device for travelin strand and strip material, tensioning means for controlling the tension in the material, fluid pressure operated double acting motor actuating means for the tensioning means. a first conduit means for supplying fluid pressure for actuating said motor means in one direction to increase the tension in the material, a second conduit means for supplying fluid pressure for actuating said motor means in the opposite direction to decrease the tension in the material, valve means operable to simultaneously increase the pressure supplied through one of the first and second conduit means to the double acting motor means and proportionately decrease the pressure supplied through the other oi said conduit means,

means responsive to the tension in the material controlling the operation or the valve means, and means for amusting the tension responsive element independently or the material and operated in response to actuation of the pressure operated means.

- WINI 'IEID B. HEINZ. 

